A repaired dishwasher ...

[RV-P]

- First of all, a little history ...
- The father of my son-in-law calls my wife and asks me if she would not want a dishwasher, instead of throwing it to the dump ... My wife agrees.
- We get the dishwasher. The person tells me that he does not take any more water and that there is a black trace on the electronic control board ...
- I disassemble the electronic card in question, I clean the black trace with a little WD40 and an old toothbrush, and what do I see? A component that looks like a transistor, but in reality is a triac, "exploded":

A small triac 600V 1A, trigger current: 3 mA.

- I search among the main suppliers of components of my island ... Alas, nothing on the horizon! Even the two Chinese suppliers of one of them do not make this kind of component ... !
- Suddenly, I remember that I had recovered the electronic module of a washing machine that was blowing my meter due to an insulation fault of the drive motor of the drum ... Immediately, I open it and I see other triacs of the same type, but different:

Triac 800V 1A, Trigger Current: 5 mA.

- Moreover, in parallel on the triac, there is a varistor which protects the triac against the tensions too strong due to the fact of cutting the supply of a coil, inductive:

The varistor, mounted in parallel between T1 and T2 of the triac.

- So, after careful reflection, it seemed useful to me to set up the new triac instead of the old one. Here's how :

Detail of the assembly of the new triac.

- Since the ATMEL control circuit is generally powered under 5V, I quickly calculate the triac control current:
- I = U / R, 5000 mV / 300 ohms = 16,67 mA. Largely enough to trigger the new triac with its 5 mA trigger current!
- I even allowed myself the luxury of mounting also the varistor protection of the triac!
- After tests, the assembly still did not work ... ! Resuming the module, testing ... There was a small 300 ohms SMD resistor cut off. As there was a free slot of a triac that was not mounted, so I replaced the resistance cut by ... his neighbor!
- Re-tests ... Eeeeennnnfinal, it works! I pass a complete cycle (3 water intakes and 3 empties), the indicator "Ende" lights up, "Good for the service"!
- It's very useful to know the main datasheets sites! You will find the characteristics of many components. Do not hesitate to put in your favorites!
- Cordially. @ +!

[izentrop]

It is not given to everyone to have your knowledge.
Manufacturers do not provide electronic card schemes in household appliances, we can not troubleshoot all the faults.
You knew that the pump was likely to be controlled by a triac and it was enough to follow his sons to find him. In addition, bursting has allowed you to discover it even more easily. Another chance also to have its reference noted on the printed circuit, which is rarely the case.

Bravo anyway, nice feat, but not accessible to everyone.

[RV-P]

- Thank you, Izentrop. But this knowledge, I acquired in self-taught! That is to say by dismantling "corpses" of electronic devices and by recovering components that can be very useful.
- But the reference triac exploded was also listed on the two neighboring triacs, not on the circuit board! And by taking the other triacs from the control module of the washing machine, I saw that it was "almost" the same!
- It is true that this kind of "specialty" is not accessible to everyone ... But at least I enjoy!
- Obviously, I do not have access to all the datasheets components exotic parfos, but I manage with those that I find!
- Cordially.
* PS: datasheet triacs used:

Z0103M.pdf

Triacs 1 A with different trigger currents.

(192.72 KB) Downloaded times 1001

[Obamot]

I love, congratulations!

Common failure on a washing machine when they turn on but do not turn anymore. We must look for the big condo that starts the engine, it is often him who is HS. (Watch out for electric shocks, in all hacks ...)

You make me want to get back to electronics, old passion! I want to "lamp" a CD player.

So you didn't use your "safety lamp" before switching on?

[RV-P]

- No need, since it was the electronic card that had dropped! It goes without saying that I tested the electovanne of water supply because it was what the triac pilot "exploded", given the color of the threads! Resistance: ~ 3,5 kiloohms, so good (To know if he takes the urge to test a solenoid valve washing machine or dishwasher!)!
- And now, since I mounted in parallel on the triac protection varistor, it is not he who will release, but perhaps the neighbors! 'Will have to think about equipping them, too ...
- You say :
"" Common failure on a washing machine when they turn on but do not turn anymore. We must look for the big condo that starts the engine, it is often him who is HS. (Beware of electric shocks, in all hacks ...) ""
*** The old washing machines were equipped with single-phase asynchronous starter motors. But now, the modern ones are equipped with universal commutator motors, like drills! In addition, there is a tachymetric generator at the end of the motor shaft, to control the washing speed and spin speeds, all controlled electronically! ***
- Cordially !

[RV-P]

- Here are the pictures of the repair of the electronic module:

The copper side module and the CMS components.

* In (1): the new Z0107NA triac (1A 800V, Ig = 5mA) mounted in place of the grilled triac.
* In (2): the small 300 ohms CMS resistor moved.
* In (3): the varistor mounted in parallel on the triac, of which we only see the welds of the pins.
- But you see other welds next to the other triacs, is not it!? ... Rest assured:

Varistors mounted in parallel on the other triacs

... is that I took the opportunity to mount the other varistors in parallel on the other triacs ! That way, they will be protected too (blue is original)!
*** In addition, I had learned from my son-in-law that this is not the first card: it had already been changed! But now, no more question than she grid!
- And more, I still have 2 other triacs on the control module of the washing machine if it was the envy of other triacs grilling in turn!
- Cordially. @ +!

[Obamot]

Hello!
Awesome!
How do you do to solder / desolder so close to an IC without it getting "hot", you have which soldering iron?

► View Text

... here I'm on standby for my switch, I'm waiting to get my hands on a power supply, I have to find it in a box in my cellar ... but there is a black cable from "com" so I'm afraid that the test will not come to the conclusion, we'll see ... it costs nothing to try and it's fun ^^

@+

[RV-P]

- A Philips 25 / 50W I recovered and, since the original fault was damaged, I adapted a Japanese soldering iron tip with the same hole!
- Of course, it is a fine, round tip, perfect for welding a wide range of components! It even allows me, as you could see, to weld CMS, not too small, however!
- Cordially.
- PS: for your black cable switch, it is certainly a cable of mass!